How To Write A Letter To Prince William. You can’t, unless you are a family member or very close friend. Officially the royals don't have surnames so when they need to write one they usually go with their parents title.
The duke of cambridge (prince william) is the second in line to the throne and the elder son of the prince of wales and diana, princess of wales. The cambridges have decided to change the way. Officially the royals don't have surnames so when they need to write one they usually go with their parents title.
